package com.jz.community.basecomm.utils;

/**
 * Created by jingzhao on 2017/9/6.
 */

import android.util.Base64;

import java.security.InvalidKeyException;
import java.security.Key;

import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import javax.crypto.spec.IvParameterSpec;

/**
 * Created by 宫智耀 on 2016/10/13.
 */
public class DES {
    // 密钥 长度不得小于24
    private final static String secretKey = "2c93cd289b311e5223303b6d153382fe";
    // 向量 可有可无 终端后台也要约定
    private final static String iv = "43123213";
    // 加解密统一使用的编码方式
    private final static String encoding = "utf-8";

    /**
     *        * 3DES加密
     *        *
     *        * @param plainText
     *        *            普通文本
     *        * @return
     *        * @throws Exception
     *       
     */
    public static String encode(String plainText, int encryptMode) throws Exception {
        Key deskey = null;
        DESedeKeySpec spec = new DESedeKeySpec(secretKey.getBytes());
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
        deskey = keyfactory.generateSecret(spec);
        Cipher cipher = Cipher.getInstance("desede/CBC/PKCS5Padding");
        IvParameterSpec ips = new IvParameterSpec(iv.getBytes());
        cipher.init(encryptMode, deskey, ips);
        byte[] encryptData = cipher.doFinal(plainText.getBytes(encoding));
        return Base64.encodeToString(encryptData, Base64.DEFAULT);
    }

    /**
     *        * 3DES解密
     *        *
     *        * @param encryptText
     *        *            加密文本
     *        * @return
     *        * @throws Exception
     *       
     */
    public static String decode(String encryptText) {
        Key deskey = null;
        DESedeKeySpec spec = null;
        try {
            spec = new DESedeKeySpec(secretKey.getBytes());
            SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
            deskey = keyfactory.generateSecret(spec);
            Cipher cipher = Cipher.getInstance("desede/CBC/PKCS5Padding");
            IvParameterSpec ips = new IvParameterSpec(iv.getBytes());
            cipher.init(Cipher.DECRYPT_MODE, deskey, ips);
            byte[] decryptData = cipher.doFinal(Base64.decode(encryptText, Base64.DEFAULT));
            return new String(decryptData, encoding);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }
}